Evaluation of previously nonscreened hereditary hemorrhagic telangiectasia patients shows frequent liver involvement and early cardiac consequences

Anaesthetic management for caesarean section in a patient with hereditary haemorrhagic telangiectasia and severe epistaxis during pregnancy

A primigravida patient, with a history of hereditary haemorrhagic telangiectasia (HHT) manifesting as nasal angiodysplasia and hepatic arteriovenous malformations (AVM), presented for delivery planning and anaesthetic evaluation at 29 weeks of gestation. She was hospitalised several times during the second and third trimester for serious recurrent epistaxis, leading to severe anaemia. In total, she required the transfusion of 20 units of packed red blood cells during her pregnancy as well as surgical nasal haemostasis under general anaesthesia (GA). The patient was referred to our tertiary centre for delivery. In the context of recurrent severe epistaxis and high cardiac output (due to hepatic AVM) in the third trimester, a multidisciplinary decision was made to plan an elective caesarean section at 35 4/7 weeks combined with nasal packing under GA. This report discusses the implications of HHT, the multidisciplinary planning of the caesarean section, intraoperative anaesthetic management and patient follow-up.

Predictors of heart failure symptoms in hereditary hemorrhagic telangiectasia patients with hepatic arteriovenous malformations

BACKGROUND

Hepatic arteriovenous malformations (AVMs) in hereditary hemorrhagic telangiectasia (HHT) patients are most commonly hepatic artery to hepatic venous shunts which can result in high-output heart failure. This condition can be debilitating and is a leading cause of liver transplantation in HHT patients. However, it is not known what characteristics can discriminate between asymptomatic patients and those who will develop heart failure symptoms.

RESULTS

176 patients with HHT were evaluated with computed tomography angiography (CTA) between April 2004 and February 2019 at our HHT Center of Excellence. 63/176 (35.8%) patients were found to have hepatic AVMs on CTA. 18 of these patients were excluded because of the presence of another condition which could confound evaluation of heart failure symptoms. In the remaining 45 patients included in our cohort, 25/45 (55.6%) patients were classified as asymptomatic and 20/45 (44.4%) were classified as symptomatic, and these groups were compared. In symptomatic patients, mean common hepatic artery (CHA) diameter was significantly higher (11.1 versus 8.4 mm) and mean hemoglobin levels were significantly lower (10.7 vs 12.6 g/dL). A stepwise multiple logistic regression analysis demonstrated that both CHA diameter and hemoglobin level were independent predictors of heart failure symptoms with ORs of 2.554 (95% CI 1.372-4.754) and 0.489 (95% CI 0.299-0.799), respectively. The receiver operator characteristic (ROC) curve of our analysis demonstrated an AUC of 0.906 (95% CI 0.816-0.996), sensitivity 80.0% (95% CI 55.7-93.4%), and specificity 75.0% (95% CI 52.9-89.4%).

CONCLUSIONS

CTA is an effective and easily reproducible method to evaluate hepatic involvement of HHT. Utilizing CTA, clinical, and laboratory data we determined CHA diameter and hemoglobin level were independent predictors of heart failure symptoms.

Minimal portosystemic encephalopathy: A new nosological entity in patients with hereditary haemorrhagic telangiectasia

BACKGROUND

Portosystemic shunts in Hereditary Haemorrhagic Telangiectasia (HHT) are often overlooked by conventional imaging although they could reduce hepatic clearance of gut-derived toxins.

AIMS

To evaluate, the presence of subclinical neurological alterations (SNAs), that we named "minimal portosystemic encephalopathy" (mPSE) in HHT patients without advanced liver disease (ALD).

METHODS

In this cross sectional study, consecutive HHT outpatients were firstly screened by critical flicker frequency (CFF) test (abnormal ≤39Hz), and the simplified animal naming test (S-ANT₁) (abnormal <15) was used to confirm the diagnosis of mPSE. Furthermore, we evaluated the effect of lactulose administration on mPSE. Multi-slice CT, cerebral dynamic magnetic resonance, laboratory analyses and transient elastography were also used.

RESULTS

None of the 37 enrolled patients showed portosystemic shunts at imaging techniques. However, 33 patients had normal CFF values (CFF-) and 4 displayed CFF alterations (37.0±0.7Hz, CFF+). The S-ANT₁ confirmed an impaired neurological performance (10.2±2.8) in CFF+ patients thus confirming the presence of mPSE. Noteworthy, lactulose administration determined a CFF increase (39.1±0.4Hz) and S-ANT₁ normalization in these patients. Neither mPSE- nor mPSE+ patients had ALD and showed similar demographic, clinical and laboratory parameters. Finally, no mPSE+ patient showed radiologically-detectable brain vascular malformations or other brain abnormalities at imaging.

CONCLUSIONS

HHT patients represent a human model of mPSE secondary to portosystemic shunts escaping radiological detection. mPSE evaluation should be incorporated in HHT surveillance protocols since it can affect both health-related/social aspects and pharmacokinetics of orally administered drugs with a narrow therapeutic index and high hepatic first-pass uptake.

Hereditary Hemorrhagic Telangiectasia Induced Portosystemic Encephalopathy: A Case Report and Literature Review

Hereditary hemorrhagic telangiectasia (HHT) is a rare disorder characterized by telangiectasias and arteriovenous malformations (AVMs), which can involve multiple organ systems. Although hepatic involvement is common, the development of portosystemic encephalopathy is extremely rare. We herein report a 72-year-old woman with HHT-induced portosystemic encephalopathy secondary to hepatic arteriovenous malformations. She presented with disturbance of consciousness, and her serum ammonia level was elevated at 270 mg/dL. Color Doppler ultrasonography and contrast-enhanced computed tomography showed hepatic AVMs and shunts, which were useful for making the definite diagnosis. Portosystemic encephalopathy should be considered as a differential diagnosis in HHT patients presenting with disturbance of consciousness.

Sequence variations of ACVRL1 play a critical role in hepatic vascular malformations in hereditary hemorrhagic telangiectasia

Background

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant disorder characterized by multiple telangiectases and caused by germline disease-causing variants in the ENG (HHT1), ACVRL1 (HHT2) and, to a lesser extent MADH4 and GDF2, which encode proteins involved in the TGF-β/BMP9 signaling pathway. Common visceral complications of HHT are caused by pulmonary, cerebral, or hepatic arteriovenous malformations (HAVMs). There is large intrafamilial variability in the severity of visceral involvement, suggesting a role for modifier genes. The objective of the present study was to investigate the potential role of ENG, ACVRL1, and of other candidate genes belonging to the same biological pathway in the development of HAVMs.

Methods

We selected 354 patients from the French HHT patient database who had one disease causing variant in either ENG or ACVRL1 and who underwent hepatic exploration. We first compared the distribution of the different types of variants with the occurrence of HAVMs. Then, we genotyped 51 Tag-SNPs from the Hap Map database located in 8 genes that encode proteins belonging to the TGF-β/BMP9 pathway (ACVRL1, ENG, GDF2, MADH4, SMAD1, SMAD5, TGFB1, TGFBR1), as well as in two additional candidate genes (PTPN14 and ADAM17). We addressed the question of a possible genetic association with the occurrence of HAVMs.

Results

The proportion of patients with germline ACVRL1 variants and the proportion of women were significantly higher in HHT patients with HAVMs. In the HHT2 group, HAVMs were more frequent in patients with truncating variants. Six SNPs (3 in ACVRL1, 1 in ENG, 1 in SMAD5, and 1 in ADAM17) were significantly associated with HAVMs. After correction for multiple testing, only one remained significantly associated (rs2277383).

Conclusions

In this large association study, we confirmed the strong relationship between ACVRL1 and the development of HAVMs. Common polymorphisms of ACVRL1 may also play a role in the development of HAVMs, as a modifying factor, independently of the disease-causing variants.

Benign Liver Tumors

Background

Due to the frequent use of medical imaging including ultrasonography, the incidence of benign liver tumors has increased. There is a large variety of different solid benign liver tumors, of which hemangioma, focal nodular hyperplasia (FNH), and hepatocellular adenoma (HCA) are the most frequent. Advanced imaging techniques allow precise diagnosis in most of the patients, which reduces the need for biopsies only to limited cases. Patients with benign liver tumors are mostly asymptomatic and do not need any kind of treatment. Symptoms can be abdominal pain and pressure effects on adjacent structures. The 2 most serious complications are bleeding and malignant transformation.

Summary

This review focuses on hepatic hemangioma (HH), FNH, and HCA, and provides an overview on clinical presentations, surgical and interventional treatment, as well as conservative management. Treatment options for HHs, if indicated, include liver resection, radiofrequency ablation, and transarterial catheter embolization, and should be carefully weighed against possible complications. FNH is the most frequent benign liver tumor without any risk of malignant transformation, and treatment should only be restricted to symptomatic patients. HCA is associated with the use of oral contraceptives or other steroid medications. Unlike other benign liver tumors, HCA may be complicated by malignant transformation. HCAs have been divided into 6 subtypes based on molecular and pathological features with different risk of complication.

Key Message

The vast majority of benign liver tumors remain asymptomatic, do not increase in size, and rarely need treatment. Biopsies are usually not needed as accurate diagnosis can be obtained using modern imaging techniques.

Hereditary hemorrhagic telangiectasia: how to efficiently detect hepatic abnormalities using ultrasonography

INTRODUCTION

Hereditary hemorrhagic telangiectasia (HHT) is a multiorgan genetic angiodysplastic affection characterized by visceral vascular malformations. It affects mainly the brains, lungs, gastrointestinal tract, and nasal mucosa. Unlike those organs, hepatic involvement, although very frequently occurring, is insufficiently recognized, mainly because of the complex vascular structure of this organ. Thus, treating HHT patients requires a solid understanding of these hepatic anomalies. It is especially important for any general clinicians to be able to recognize clinical findings in HHT, which leads to a high suspicion of HHT and have an index of suspicion for liver abnormalities of HHT. For this purpose, keen awareness of clinical as well as hepatic sonographic (US) findings is paramount.

AIM

The aim of this review is to summarize previously reported findings on the hepatic US through a thorough analysis of related articles, and to (a) determine the role of US in the diagnosis of hepatic involvement in HHT patients and (b) propose the most simple and easy way to detect HHT-related abnormalities during routine US examinations.

CONCLUSION

Hepatic US serves to diagnose the detailed complex hepatic changes typical of HHT, and contributes to increased diagnostic confidence of hepatic changes in HHT patients, with the most simple way not to overlook HHT-related abnormalities being to find hepatic artery dilatation.

ACG Clinical Guideline: Disorders of the Hepatic and Mesenteric Circulation

Disorders of the mesenteric, portal, and hepatic veins and mesenteric and hepatic arteries have important clinical consequences and may lead to acute liver failure, chronic liver disease, noncirrhotic portal hypertension, cirrhosis, and hepatocellular carcinoma. Although literature in the field of vascular liver disorders is scant, these disorders are common in clinical practice, and general practitioners, gastroenterologists, and hepatologists may benefit from expert guidance and recommendations for management of these conditions. These guidelines represent the official practice recommendations of the American College of Gastroenterology. Key concept statements based on author expert opinion and review of literature and specific recommendations based on PICO/GRADE analysis have been developed to aid in the management of vascular liver disorders. These recommendations and guidelines should be tailored to individual patients and circumstances in routine clinical practice.

Liver involvement in hereditary hemorrhagic telangiectasia

Liver vascular malformations (VMs) in hereditary hemorrhagic telangiectasia (HHT) are typically diffuse and can evolve from small telangiectasias to large arteriovenous malformations, with various stages of severity. Doppler US is the ideal first-line investigation for the assessment of liver VMs in HHT due to its safety, tolerability, low costs, and accuracy for the detection of liver VMs. The caliber, course, and flow characteristics in the hepatic artery, portal vein, and hepatic vein as determined by Doppler US, together with parenchymal abnormalities, support the diagnosis of liver VMs in HHT and their severity staging. When Doppler US expertise is lacking or an assessment of HHT patients with symptoms/signs suggestive of complicated liver VMs is required, particularly if OLT is considered, multiphase CT or MRI is suitable to investigate symptomatic liver VMs. Liver biopsy is neither necessary for the diagnosis of hepatic VMs related to HHT nor should be considered in HHT patients with liver mass/es suggestive of focal nodular hyperplasia.

Pulmonary hypertension subtypes associated with hereditary haemorrhagic telangiectasia: Haemodynamic profiles and survival probability

BACKGROUND

Different pulmonary hypertension (PH) mechanisms are associated with hereditary haemorrhagic telangiectasia (HHT).

METHODS AND RESULTS

We conducted a retrospective study of all suspected cases of PH (echocardiographically estimated systolic pulmonary artery pressure [sPAP] ≥ 40 mmHg) in patients with definite HHT recorded in the French National Reference Centre for HHT database. When right heart catheterization (RHC) was performed, PH cases were confirmed and classified among the PH groups according to the European guidelines. Among 2,598 patients in the database, 110 (4.2%) had suspected PH. Forty-seven of these 110 patients had RHC: 38/47 (81%) had a confirmed diagnosis of PH. The majority of these had isolated post-capillary PH (n = 20). We identified for the first time other haemodynamic profiles: pre-capillary pulmonary arterial hypertension (PAH) cases (n = 3) with slightly raised pulmonary vascular resistances (PVR), and combined post- and pre-capillary PH cases (n = 4). Compared to controls, survival probability was lower in patients with PAH.

CONCLUSION

This study revealed the diversity of PH mechanisms in HHT. The description of combined post- and pre-capillary PH with/or without high cardiac output (CO) suggests either a continuum between the pre- and post-capillary haemodynamic profiles or a different course in response to high CO.

The Lung in Hereditary Hemorrhagic Telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is a dominantly inherited genetic vascular disorder with an estimated prevalence of 1 in 6,000, characterized by recurrent epistaxis, cutaneous telangiectasia, and arteriovenous malformations (AVMs) that affect many organs including the lungs, gastrointestinal tract, liver, and brain. Its diagnosis is based on the Curaçao criteria, and is considered definite if at least 3 of the 4 following criteria are fulfilled: (1) spontaneous and recurrent epistaxis, (2) telangiectasia, (3) a family history, and (4) pulmonary, liver, cerebral, spinal, or gastrointestinal AVMs. The focus of this review is on delineating how HHT affects the lung.

Conditional knockout of activin like kinase-1 (ALK-1) leads to heart failure without maladaptive remodeling

Activin like kinase-1 (AlK-1) mediates signaling via the transforming growth factor beta (TGFβ) family of ligands. AlK-1 activity promotes endothelial proliferation and migration. Reduced AlK-1 activity is associated with arteriovenous malformations. No studies have examined the effect of global AlK-1 deletion on indices of cardiac remodeling. We hypothesized that reduced levels of AlK-1 promote maladaptive cardiac remodeling. To test this hypothesis, we employed AlK-1 conditional knockout mice (cKO) harboring the ROSA26-CreER knock-in allele, whereby a single dose of intraperitoneal tamoxifen triggered ubiquitous Cre recombinase-mediated excision of floxed AlK-1 alleles. Tamoxifen treated wild-type (WT-TAM; n = 5) and vehicle treated AlK-1-cKO mice (cKO-CON; n = 5) served as controls for tamoxifen treated AlK-1-cKO mice (cKO-TAM; n = 15). AlK-1 cKO-TAM mice demonstrated reduced 14-day survival compared to cKO-CON controls (13 vs 100%, respectively, p < 0.01). Seven days after treatment, cKO-TAM mice exhibited reduced left ventricular (LV) fractional shortening, progressive LV dilation, and gastrointestinal bleeding. After 14 days total body mass was reduced, but LV and lung mass increased in cKO-TAM not cKO-CON mice. Peak LV systolic pressure, contractility, and arterial elastance were reduced, but LV end-diastolic pressure and stroke volume were increased in cKO-TAM, not cKO-CON mice. LV AlK-1 mRNA levels were reduced in cKO-TAM, not cKO-CON mice. LV levels of other TGFβ-family ligands and receptors (AlK5, TBRII, BMPRII, Endoglin, BMP7, BMP9, and TGFβ1) were unchanged between groups. Cardiomyocyte area and LV levels of BNP were increased in cKO-TAM mice, but LV levels of β-MHC and SERCA were unchanged. No increase in markers of cardiac fibrosis, Type I collagen, CTGF, or PAI-1, were observed between groups. No differences were observed for any variable studied between cKO-CON and WT-TAM mice. Global deletion of AlK-1 is associated with the development of high output heart failure without maladaptive remodeling. Future studies exploring the functional role of AlK-1 in cardiac remodeling independent of systemic AVMs are required.

Hereditary hemorrhagic telangiectasia: to transplant or not to transplant?

This report comments the case reported by Muller et al. which describes a combination of at least two different indications for orthotopic liver transplant (OLT) in a same patient: hepatocarcinoma and HHT complicated with severe liver involvement and high output cardiac failure. This case report highlighted that the clear time for OLT in HHT can be difficult to determine. In HHT, if intensive medical approach is not efficient, OLT, has to be considered. In the case of Muller et al., the patient was correctly listed for OLT for a single hepatocellular carcinoma, however, he did not receive a sufficient priority so as to avoid worsening of liver vascular malformations complications. Bevacizumab may be a therapeutic option in the treatment of complicated liver VMs in HHT, However, the recurrence of symptoms after withdrawal of the drug make it unsuitable as a replacement for OLT in the cure of complicated liver VMs in HHT. In the case reported by Muller et al. the right "OLT window" after bevacizumab was lost. The right time for OLT in severe complicated liver VMs in HHT does exist but, as this case illustrates, it can be very difficult to determine. As OLT is a radical cure for liver VMs, with excellent outcomes, it should be the therapeutic choice in patients under the age of 65 years. Bevacizumab may be an interesting option, either for patients over the age of 65 years, or those who are poor candidates for surgery; if these latter respond to bevacizumab they should be re- evaluated for OLT (with a "fast- track") as the prognosis of severe complicated liver VMs is very poor.

Bleeding and clotting in hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is a relatively common inherited vascular disorder that was first described in 1864, and is notable for epistaxis, telangiectasia, and arterial venous malformations. While genetic tests are available, the diagnosis remains clinical, and is based on the Curacao criteria. Patients with HHT are at increased risk for both bleeding and clotting events. Because of these competing complications, hematologists are often faced with difficult clinical decisions. While the majority of management decisions revolve around bleeding complications, it is not infrequent for these patients to require anticoagulation for thrombosis. Any anticoagulation recommendations must take into account the bleeding risks associated with HHT. Recent reviews have found that HHT patients can be safely anticoagulated, with the most frequent complication being worsened epistaxis. Large clinical trials have shown that factor IIa and Xa inhibitors have less intracranial bleeding than warfarin, and basic coagulation research has provided a possible mechanism. This article describes the anticoagulation dilemma posed when a 62-year-old female patient with a history of bleeding events associated with HHT was diagnosed with a pulmonary embolism. The subsequent discussion focuses on the approach to anticoagulation in the HHT patient, and addresses the role of the new oral anticoagulants.

Identifying the presence of clinically significant hepatic involvement in hereditary haemorrhagic telangiectasia using a simple clinical scoring index

BACKGROUND & AIMS

Though hepatic involvement is common in patients with hereditary haemorrhagic telangiectasia (HHT), symptomatic liver disease is rare but potentially fatal without liver transplantation. Factors associated with clinically significant liver disease in patients with HHT are unknown.

METHODS

In this prospective cohort study, we included consecutive patients from 2001 to 2011 with definite HHT, who underwent systematic protocol screening including contrast-enhanced hepatic CT and/or abdominal ultrasound. Using a multivariable logistic regression model, we developed a simple clinical scoring index to identify the presence of symptomatic liver disease (cardiac failure, portal hypertension, or biliary disease) or 'at-risk' liver disease (asymptomatic patients, with hepatic bruit, abnormal liver biochemistry, or elevated cardiac index).

RESULTS

Of 316 patients with definite HHT, 171 patients (54.1%; age 53.4 ± 15.2 y, 101 females) had hepatic involvement on imaging. Twenty-nine patients had symptomatic liver disease (22 patients with high-output heart failure); 45 patients were 'at-risk' for liver disease. Using multivariable logistic regression analysis, we derived a score using age, gender, hemoglobin and alkaline phosphatase at presentation which could accurately distinguish patients with clinically significant liver involvement from patients with no or incidental liver lesions (c-statistic=0.80). A score <3 indicated low risk (<5%) and score >6 indicated high risk (>80%) of harboring clinically significant liver disease in HHT.

CONCLUSIONS

A simple scoring system can distinguish patients at low, moderate, and high risk of harboring clinically significant liver disease. With validation, this score may be used to identify patients for individualized screening and enrollment in clinical trials.

High prevalence of pulmonary hypertension in patients with hereditary hemorrhagic telangiectasia

OBJECTIVE

Hereditary hemorrhagic telangiectasia (HHT) is a vascular disorder causing mucocutaneous telangiectases and visceral arteriovenous malformations (AVMs). Pulmonary hypertension (PH) is considered an uncommon complication of HHT whose impact on the survival of these patients is currently unknown.

METHODS

From January 1995 to December 2008, 29 hospitalized patients with definite HHT were included and followed until January 2011. Data on demographics, clinical symptoms and survival were recorded. PH was classified according to echocardiographic probability.

RESULTS

A CT angiogram was performed in 24 of the 29 patients with HHT and AVMs were detected in 16 of them (67%): hepatic in 58%, pulmonary in 33% and spinal in 3%; 37% had both pulmonary and hepatic AVMs. Transthoracic Doppler echocardiography (TTE) was performed in 21 patients. PH was considered possible in 4 (14%) and probable in 9 (31%). The mean age at diagnosis was lower in patients with PH than in patients without PH (54±16.5 years vs 73±8.8 years, p=0.002). PH was more prevalent in patients with AVMs (56 vs. 23%, p=0.036). The mean follow-up of the entire cohort was 6±4.4 years (range: 2 months-17 years), during this time 18 patients died (62%; mean age 73±8.1 years). Patients with PH died at a younger age (68±8.4 vs. 79±2.7 years, p=0.015) than those without PH.

CONCLUSIONS

PH is a severe condition that significantly reduces survival on HHT patients. PH should be suspected in all HHT patients with dyspnea and hepatic AVMs.

Hereditary hemorrhagic telangiectasia, liver vascular malformations and cardiac consequences

BACKGROUND

HHT patients with liver vascular malformations (VMs) may develop high-output cardiac failure requiring liver transplant in few cases.

OBJECTIVE

Our aim is to show that echocardiography is a good tool to evaluate the severity of hepatic vascular malformations in HHT and can improve medical management in HHT patients.

METHODS

The study is a cross-sectional study of cardiac parameters in HHT patients with dyspnea in a single referral center. All HHT patients with dyspnea, consecutively seen at HHT reference center in Lyon between May 2007 and November 2009 were included and had hepatic vascular Ultrasound and Echocardiography. Echocardiographic measures included cardiac output (CO) and index (CI), left ventricle (LV) filling pressures, and pulmonary artery pressure. Then, patients were classified in 4 groups according to the severity: group 1 (normal values), group 2 with isolated high CI, group 3 with high CI and increased LV-filling pressures and group 4 with increased LV-filling pressures and pulmonary hypertension.

RESULTS

Fifty-two HHT-patients were analyzed. Eight patients were in group 1, 25 in group 2, 6 in group 3 and 13 in group 4. Age, NYHA class dyspnea, edema, atrial fibrillation, hepatic artery diameter, and BNP (brain natriuretic peptide) levels significantly increased from groups 1 to 4 as well as left atrial area, and presence of mitral regurgitation. Patients with associated pulmonary VMs (n=11) did not show any clinical or echocardiographic differences.

CONCLUSION

Performing echocardiography in HHT patients with dyspnea allowed us to better understand the physiological processes of high-CO failure complicating liver vascular malformations and may improve follow-up of patients and treatment decisions.

Liver involvement in hereditary hemorrhagic telangiectasia: can breath test unmask impaired hepatic first-pass effect?

Hepatic arteriovenous malformations (HAVMs) in hereditary hemorrhagic telangiectasia (HHT) have long been considered to have scarce clinical significance in most cases. Nevertheless, data are lacking regarding the influence of HAVMs on the liver first-pass effect on drugs in HHT patients. To gain insight into the effect of HAVMs on hepatic drug clearance by means of two specific (13)C-labeled probes, namely the (13)C-methacetin and (13)C-aminopyrine, 46 HHT patients and 44-matched healthy controls were enrolled. The liver first-pass effect was studied by the (13)C-based breath test using methacetin and aminopyrine. The methacetin breath test showed statistically significant reduced metabolism rates (p < 0.0001) in HHT when compared with controls, both in patients with and without CT-detectable HAVMs, and when expressed both as cumulative (13)C-percentage dose per hour and as (13)C-percentage peak after 15 min. In contrast, no significant difference was found between HHT and controls regarding aminopyrin metabolism rates. In HHT, (13)C%-methacetin breath test values are significantly lower than those found in normal subjects, probably due to the effect of hepatic shunts. A reduced perfusion and an impaired hepatic metabolism might affect hepatic drug clearance in HHT. Therefore, an appropriate dosage adjustments should be considered when high-hepatic-metabolism drugs are administered to HHT patients.

Spontaneous thrombosis of an orbital arteriovenous malformation revealing hereditary haemorrhagic telangiectasia (Rendu-Osler-Weber disease). A case report

Hereditary Haemorrhagic Telangiectasia (HHT) is a genetic disorder responsible for cutaneous or mucosal telangiectasia and arteriovenous malformations (AVMs). The most frequent locations are lung and brain. In contrast, orbital AVMs are very rare. We describe a case of symptomatic orbital arteriovenous malformation due to spontaneous thrombosis. A 65-year-old woman was referred for chronic right eye proptosis associated with dilation of conjunctival vessels with a jellyfish pattern. Right visual acuity was 20/40 and intraocular pressure was 40 mmHg. Personal and familial history of recurrent epistaxis, associated with multiple telangiectasia within lips and palate, led to the diagnosis of HHT. Magnetic resonance imaging (MRI) completed with cerebral angiography found a giant and occluded AVM within the right orbit. Other AVMs were also found in brain and chest, confirming the diagnosis. Antiglaucomatous eyedrops were added to reduce intraocular pressure and a steroid therapy was begun. Two months later, visual acuity decreased in the right eye, due to a central retinal vein thrombosis. In conclusion, Most brain or pulmonary AVM can be treated by embolization. By contrast, this treatment in case of orbital location can lead to central retinal artery and/or central retinal vein occlusion, which may also appear as a spontaneous complication of the orbital AVM. Therapeutic management of orbital AVM is thus not standardized, and the balance between spontaneous and iatrogenic risk of visual loss has to be taken into account.

Abcc6 deficiency causes increased infarct size and apoptosis in a mouse cardiac ischemia-reperfusion model

OBJECTIVE

ABCC6 genetic deficiency underlies pseudoxanthoma elasticum (PXE) in humans, characterized by ectopic calcification, and early cardiac disease. The spectrum of PXE has been noted in Abcc6-deficient mice, including dystrophic cardiac calcification. We tested the role of Abcc6 in response to cardiac ischemia-reperfusion (I/R) injury.

METHODS AND RESULTS

To determine the role of Abcc6 in cardioprotection, we induced ischemic injury in mice in vivo by occluding the left anterior descending artery (30 minutes) followed by reperfusion (48 hours). Infarct size was increased in Abcc6-deficient mice compared with wild-type controls. Additionally, an Abcc6 transgene significantly reduced infarct size on the background of a naturally occurring Abcc6 deficiency. There were no differences in cardiac calcification following I/R, but increased cardiac apoptosis was noted in Abcc6-deficient mice. Previous studies have implicated the bone morphogenetic protein (BMP) signaling pathway in directing calcification, and here we showed that the BMP responsive transcription factors pSmad1/5/8 were increased in hearts of Abcc6 mice. Consistent with this finding, BMP4 and BMP9 were increased and activin receptor-like kinase-2 and endoglin were downregulated in cardiac extracts from Abcc6-deficient mice versus controls.

CONCLUSIONS

These data identify Abcc6 as a novel modulator of cardiac myocyte survival after I/R. This cardioprotective mechanism may involve inhibition of the BMP signaling pathway, which modulates apoptosis.

Dynamic 4D MR angiography versus multislice CT angiography in the evaluation of vascular hepatic involvement in hereditary haemorrhagic telangiectasia

PURPOSE

Hereditary haemorrhagic telangiectasia (HHT), or Rendu-Osler-Weber disease, is a rare autosomal dominant disorder characterised by mucocutaneous or visceral vascular abnormalities that may be widely distributed throughout the cardiovascular system. The purpose of this study was to compare multislice computed tomography angiography (MSCTA) and 4D dynamic contrast-enhanced magnetic resonance angiography (D-MRA) for evaluating vascular hepatic involvement in patients with HHT.

MATERIALS AND METHODS

Fifty-two consecutive HHT patients underwent MSCTA and D-MRA examinations for systematic analysis of vascular visceral involvement. The images from the two techniques were reviewed independently by two expert radiologists to identify the following vascular abnormalities: telangiectases or large vascular masses; perfusion disorders [transient hepatic attenuation differences (THADs)]; hepatic arteriovenous malformations (HAVMs). Data, as well as diameters of the common hepatic artery and portal vein, were compared with Cohen's kappa statistic, Student's t test and receiver operating characteristic (ROC) curve analysis, as appropriate.

RESULTS

Both MSCTA and D-MRA detected one or more of the following hepatic vascular abnormalities in 36/52 cases (telangiectases in 29/52, THADs in 23/52 and HAVMs in 25/52[CE1]). A good concordance was found between the two techniques when determining the type of hepatic shunt (κ=0.9). No statistically significant differences were found when comparing mean common hepatic artery and portal vein diameters (p=0.09 and 0.22, respectively) and their accuracy in predicting HAVMs.

CONCLUSIONS

D-MRA has the same diagnostic accuracy as MSCTA and has the advantage of being less invasive due to the absence of ionising radiation.

Natural history and outcome of hepatic vascular malformations in a large cohort of patients with hereditary hemorrhagic teleangiectasia

BACKGROUND

Hereditary hemorrhagic telangiectasia is a genetic disease characterized by teleangiectasias involving virtually every organ. There are limited data in the literature regarding the natural history of liver vascular malformations in hemorrhagic telangiectasia and their associated morbidity and mortality.

AIM

This prospective cohort study sought to assess the outcome of liver involvement in hereditary hemorrhagic telangiectasia patients.

METHODS

We analyzed 16 years of surveillance data from a tertiary hereditary hemorrhagic telangiectasia referral center in Italy. We considered for inclusion in this study 502 consecutive Italian patients at risk of hereditary hemorrhagic telangiectasia who presented at the hereditary hemorrhagic telangiectasia referral center and underwent a multidisciplinary screening protocol for the diagnosis of hereditary hemorrhagic telangiectasia. Of the 502 individuals assessed in the center, 154 had hepatic vascular malformations and were the subject of the study; 198 patients with hereditary hemorrhagic telangiectasia and without hepatic vascular malformations were the controls. Additionally, we report the response to treatment of patients with complicated hepatic vascular malformations.

RESULTS

The 154 patients were included and followed for a median period of 44 months (range 12-181); of these, eight (5.2%) died from VM-related complications and 39 (25.3%) experienced complications. The average incidence rates of death and complications were 1.1 and 3.6 per 100 person-years, respectively. The median overall survival and event-free survival after diagnosis were 175 and 90 months, respectively. The rate of complete response to therapy was 63%.

CONCLUSIONS

This study shows that substantial morbidity and mortality are associated with liver vascular malformations in hereditary hemorrhagic telangiectasia patients.

Molecular diagnosis in hereditary hemorrhagic telangiectasia: findings in a series tested simultaneously by sequencing and deletion/duplication analysis

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder characterized by a unique pattern of telangiectasia and arteriovenous malformations (AVMs). Mutations in one of two genes (ENG and ACVRL1) cause approximately 85% of cases. Genetic testing impacts clinical management because genotype/phenotype correlations exist, and early preventive screening for internal AVMs is recommended in affected individuals prior to the age at which a diagnosis can typically be made based on clinical criteria. We report 383 consecutive cases in which sequencing and large deletion/duplication analysis were performed simultaneously for endoglin (ENG) and activin-like receptor kinase 1 (ACVRL1). We report the first case of mosaicism in an affected individual and 61 novel mutations. We discuss the potential benefits of a diagnostic testing approach for HHT whereby ENG and ACVRL1 are analyzed simultaneously by sequencing and a method which detects large deletion/duplications, rather than by a sequential or reflex testing protocol. We report a case in which a deletion would probably have been missed if large deletion/duplication analysis was performed only if a suspected pathogenic mutation was not first identified by sequencing.

Large spectrum of liver vascular lesions including high prevalence of focal nodular hyperplasia in patients with hereditary haemorrhagic telangiectasia: the Belgian Registry based on 30 patients

OBJECTIVES

We report the Belgian Registry of 30 patients (19 women and 11 men) with hereditary haemorrhagic telangiectasia (HHT) and liver involvement.

RESULTS

Twenty-three patients (77%) were asymptomatic. Within the seven symptomatic patients (23%), four suffered from high output cardiac failure, two died before liver transplantation and one was transplanted. Three patients developed symptomatic biliary disease, two were transplanted and one was listed. Intrahepatic shunts and a large hepatic artery (6-14 mm, mean: 9.3 mm) were found in all patients and are characteristic of liver involvement. We observed a high prevalence (47%) of asymptomatic hepatic tumours with radiological and histological characteristics of focal nodular hyperplasia (FNH) for the majority of these tumours. The histological examination of the three explanted livers revealed the coexistence of a large spectrum of hepatic vascular lesions including intrahepatic shunts, FNH, nodular regenerative hyperplasia, sinusoidal dilatation and ischaemic cholangiopathy. All these lesions should be diagnosed early to avoid invasive procedures even if a liver biopsy was performed in six of our patients without complications. The liver biopsy led to the diagnosis of HHT in one patient and to FNH in another one.

CONCLUSION

Liver involvement in HHT is characterized by a high prevalence of FNH and a large spectrum of vascular lesions such as intrahepatic shunts, nodular regenerative hyperplasia, sinusoidal dilatation and ischaemic cholangiopathy that may coexist simultaneously in the same patient.

Hereditary haemorrhagic telangiectasia: pathophysiology, diagnosis and treatment

Hereditary haemorrhagic telangiectasia, inherited as an autosomal dominant trait, affects approximately 1 in 5000 people. The abnormal vascular structures in HHT result from mutations in genes (most commonly endoglin or ACVRL1) whose protein products influence TGF-ß superfamily signalling in vascular endothelial cells. The cellular mechanisms underlying the generation of HHT telangiectasia and arteriovenous malformations are being unravelled, with recent data focussing on a defective response to angiogenic stimuli in particular settings. For affected individuals, there is often substantial morbidity due to sustained and repeated haemorrhages from telangiectasia in the nose and gut. Particular haematological clinical challenges include the management of severe iron deficiency anaemia; handling the intricate balance of antiplatelet or anticoagulants for HHT patients in whom there are often compelling clinical reasons to use such agents; and evaluation of apparently attractive experimental therapies promoted in high profile publications when guidelines and reviews are quickly superseded. There is also a need for sound screening programmes for silent arteriovenous malformations. These occur commonly in the pulmonary, cerebral, and hepatic circulations, may haemorrhage, but predominantly result in more complex pathophysiology due to consequences of defective endothelium, or shunts that bypass specific capillary beds. This review will focus on the new evidence and concepts in this complex and fascinating condition, placing these in context for both clinicians and scientists, with a particular emphasis on haematological settings.